"For years, when spring rolled around in St. Louis, Mich., songbirds dropped to the ground, dead.
Locals often found them lying facedown in their yards. On occasion, they watched the birds — mostly robins — convulse and shudder until their hearts stopped beating. Sometimes cats dragged the bodies away before anyone noticed.
In 2012, residents collected 94 bird corpses and took them to a lab for testing."